CVE-2025-5803 identifies a missing authorization vulnerability in the VikBooking Hotel Booking Engine & PMS, versions up to and including 1.8.2. This vulnerability arises because the application fails to properly verify whether a user has the necessary permissions before allowing access to certain functions or data. The flaw can be exploited remotely over the network (AV:N) with low attack complexity (AC:L), requiring only limited privileges (PR:L) and no user interaction (UI:N). The scope is unchanged (S:U), but the impact on confidentiality, integrity, and availability is high (C:H/I:H/A:H), indicating that an attacker could access sensitive booking data, modify or delete records, and disrupt service availability. The vulnerability affects a critical component in the hospitality sector, responsible for managing hotel bookings and property management system (PMS) operations. Although no public exploits are currently known, the high CVSS score of 8.8 reflects the serious risk posed. The vulnerability was reserved in June 2025 and published in November 2025, indicating recent discovery. The lack of available patches at the time of reporting necessitates immediate mitigation efforts by affected organizations. The vulnerability’s exploitation could lead to unauthorized data access, manipulation of bookings, and potential denial of service, severely impacting hotel operations and customer trust.

For European organizations, especially those in the hospitality and tourism sectors, this vulnerability poses a significant risk. Exploitation could lead to unauthorized access to sensitive customer data, including personal identification and payment information, violating GDPR and other data protection regulations. Integrity of booking and PMS data could be compromised, leading to fraudulent bookings, cancellations, or financial losses. Availability impacts could disrupt hotel operations, causing reputational damage and loss of revenue. Given the importance of tourism to many European economies, such disruptions could have broader economic consequences. Additionally, the breach of customer data could trigger regulatory fines and legal liabilities. Organizations using VikBooking PMS must consider the threat as critical to their operational security and compliance posture.

1. Immediately audit and restrict user privileges within the VikBooking system to the minimum necessary, ensuring that only authorized personnel have access to sensitive functions. 2. Implement network segmentation and firewall rules to limit access to the PMS backend to trusted IP addresses and internal networks. 3. Monitor logs and system activity for unusual access patterns or privilege escalations indicative of exploitation attempts. 4. Engage with the vendor or community to obtain patches or updates addressing CVE-2025-5803 as soon as they become available. 5. Until patches are applied, consider deploying Web Application Firewalls (WAFs) with custom rules to detect and block unauthorized access attempts targeting the vulnerable endpoints. 6. Conduct regular security assessments and penetration testing focused on authorization controls within the PMS environment. 7. Educate staff on the importance of access controls and prompt reporting of suspicious system behavior. 8. Prepare incident response plans specific to PMS compromise scenarios to minimize impact if exploitation occurs.